The most common and most likely answer to this crossword clue is the 7 letter word DIPTERA
I've seen this crossword clue in The Guardian
D
I
P
T
E
R
A
More clues leading to the result DIPTERA
- Flies partied, buzzing around
- Flies parted, I pissed
- Flies are pulled up after donning immaculately pressed trousers, originally
- With lower temperature, time flies
- Rapid winds into which hollow tree flies
- Mosquitoes, for example, swim – a trillion!
- Flies lower rate flying
- Look through Times on order of insects
- PA tried various fliers
- Flies in the face of danger, one party’s leader: that’s final, period
Buddy explains!
The straight part
We know that "fliers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fliers = diptera.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.